context a minute ago. It was ([Leaf 1], []). If we add it here, we get:
Branch (Leaf 2, Leaf 3), ([], [Leaf 4], ([Leaf 1], [])
context a minute ago. It was ([Leaf 1], []). If we add it here, we get:
Branch (Leaf 2, Leaf 3), ([], [Leaf 4], ([Leaf 1], [])